This invention concerns the prevention of detonation of a quantity of explosive powder, in a bulk handling system, which would otherwise result from deflagration of the powder within the system.
In the manufacture of explosive or incendiary devices, such as certain types of ammunition, and the like, large quantities of explosive material, such as smokeless powder and the like, must frequently be transferred from place to place.
Transport, and temporary storage, of such volumes of such material is, of course, dangerous since ignition thereof may result in detonation, with catastrophic results. This danger requires that the utmost precautions be taken, including the abolition of smoking, matches, lighters, and other devices which could cause ignition of the powder.
Notwithstanding such safety precautions, accidental powder ignition may still occur as a result of any of a number of causes which the most stringent safety precautions can minimize, but not eliminate.
This invention concerns the prevention of detonation of a quantity of explosive material being transported, or temporarily stored, even if deflagration thereof occurs. It is known that detonation of a confined mass of explosive powder will occur once heat and gas pressure, caused by combustion gases produced by the burning powder, become sufficient to cause the burning rate of the powder to reach a mass detonation rate, at which time all of the powder is substantially instantaneously consumed, causing an explosion. If the stored powder burns at a rate which is less than the mass detonation rate, no explosion will occur, and the powder will merely burn itself up. The safety drive of this invention provides for pressure relief of the burning powder, whereby the burning rate is prevented from increasing to the mass detonation rate.
The pressure relief is provided by means of a device disposed in a vertical powder transport system and comprising a chamber having a plurality of wall members operable in response to an increase in chamber pressure. Preferably, the chamber includes a central portion opening upwardly into a plurality of prismatic wing portions, the top wall member of each prism being raised in response to elevated chamber pressure so as to provide a means of escape for gases produced by powder combustion.